Hydraulic excavators, bulldozers, and other work machines are equipped with a track travel device. A track constituting the track travel device includes a plurality of track links, which are connected endlessly, and track shoes, which are fixed to the corresponding track links. Each track shoe includes a plate portion having a plate shape, and a grouser portion protruding from the plate portion. During traveling with the track travel device, the track rotates while the grouser portions of the track shoes are engaging the ground. This causes the grouser portions to wear out earlier than the plate portions. Advanced wear of the grouser portions will adversely affect the traveling with the track travel device, so the track shoes are replaced, for example.
However, it is often the case that even when a grouser portion has worn out, the corresponding plate portion is still usable. In such a case, replacing the track shoe as a whole is not cost-effective. Thus, the track shoe with its grouser portion worn out may be subjected to repair, in which a lug bar having a similar shape as the original grouser portion is placed on that track shoe by welding or other means (see, for example, Japanese Patent Application Laid-Open No. 2004-58688 (Patent Literature 1)).